Test ID CARTF Carbamazepine Profile, Serum
Useful For
Monitoring patients exhibiting symptoms of carbamazepine toxicity whose total serum carbamazepine concentration is within the therapeutic range, but who may be producing significant levels of the active metabolite epoxide
Free carbamazepine concentration may also be useful to monitor in patients with altered or unpredictable protein binding capacity
Specimen Type
Serum RedSpecimen Required
Container/Tube: Red top
Specimen Volume: 2 mL
Submission Container/Tube: Plastic vial
Collection Instructions:
1. Draw blood 12 hours (trough value) after last dose.
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum Red | Refrigerated (preferred) | 7 days |
| Frozen | 28 days | |
| Ambient | 48 hours |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Reference Values
CARBAMAZEPINE, TOTAL
Therapeutic: 4.0-12.0 mcg/mL
Critical value: ≥15.0 mcg/mL
CARBAMAZEPINE-10,11-EPOXIDE
Therapeutic: 0.4-4.0 mcg/mL
Toxic concentration: ≥8.0 mcg/mL
CARBAMAZEPINE, FREE
Therapeutic: 1.0-3.0 mcg/mL
Critical value: ≥4.0 mcg/mL
Day(s) Performed
CARTA, CARF: Monday through Sunday
1011E: Tuesday
Report Available
Same day/1 to 7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
80156-Carbamazepine, total
80157-Carbamazepine, free
80161-Carbamazepine-10,11-Epoxide
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.